Vue.js Check/Detect Is Prerender Environment

const path = require('path')const PrerenderSPAPlugin = require('prerender-spa-plugin')const Renderer = PrerenderSPAPlugin.PuppeteerRenderermodule.exports = {  configureWebpack:  {    plugins: process.env.NODE_ENV === 'production' ? [      new PrerenderSPAPlugin({        // Required - The path to the webpack-outputted app to prerender.        staticDir: path.join(__dirname, 'dist'),        // To check/detect is prerender environment        renderer: new Renderer({          injectProperty: '__PRERENDER_INJECTED',          inject: { // required, else window['__PRERENDER_INJECTED'] is not created            foo: 'bar'          },        }),        // Required - Routes to render.        routes: [ '/', '/about', '/day/2019-10-18', '/card/qGNpbK3R7ne0siTNPTya'],      })    ] : []  }}

const isPrerender = '__PRERENDER_INJECTED' in window